Sure, but that’s not saying much. Planning is really about communication. If you only have one author (like the prequels) then you have a much lower need for planning.
ANH, ESB, and RotJ each had different writers and directors working without a plan, but at least they all had the same editor (who notably didn’t shy away from rewriting the story in post). Even so, Star Wars was clearly starting to go off the rails by RotJ with its twists and reveals. They needed another big reveal like ESB so they pulled the twin sister thing out of their butts. If they’d made Episode 7 in 1986 it probably would have revealed that Han Solo is Luke’s mom.
The prequels were not planned at all. Lucas was a notorious procrastinator and didn’t deliver the screenplays until the last minute. Basically all they ever had was “obi wan trains Vader and then vader knocks up a girl and then obi wan and Vader fight in a volcano”, and Lucas winged the rest.
So really the problem here is that Lucasfilms not a very good studio. They have a long history of mismanaging properties. What Disney should have done is bought the IP and shuttered Lucasfilm, but like I said that goes at right angles to how acquisitions typically work.
Its hard to say. I mean, empirically. It’s really hard to figure out how well brand advertising works, for example, so it’s correspondingly hard to figure out how much brands have been damaged in the long term.
So, like, imagine these movies had Coca-cola tie ins: coca-cola presents Star Wars the force awakens. Now you associate coca-cola with a dumb boring movie. How much was coca-colas brand damaged by that? Hard to say.
Short term, it’s definitely lost cachet with the public and critics. There’s just less interest in seeing Star Wars movies now. Licensees have also lost interest, but that’s because nobody wants to buy toys based on a dumb boring movie - they’ll come back when the money does. It probably also hasn’t affected their core audience much, if they ever figure out how to make a new TIE Fighter game (even their core audience isn’t buying new trilogy merch).
if the name “Star Wars” has been subconsciously associated with “boring ****”, though, then it’s kinda over.